Assignment Instructions POWER ANALYSIS Assignment Instructions This is a three-p

For This or a Similar Paper Click To Order Now

Assignment Instructions
POWER ANALYSIS
Assignment Instructions
This is a three-part assignment in which you will demonstrate your ability to:
Analyze components of a t-test required for power analysis.
Compute and interpret a post-hoc power analysis.
Compute and interpret an a priori power analysis.
In addition to your statistical software, you will also use the G*Power 3 software to complete this assignment. Answer each question, providing statistical software or G* Power analysis output when necessary to support your answer.
Use the data file provided by your instructor for this assignment. You will be conducting a post-hoc power analysis and an a priori power analysis on an independent samples t-test with extra credit as the grouping variable (no = 1; yes = 2) and Total as the outcome variable. There are three sections of this assignment. After reporting the t-test results, you will then conduct a post-hoc power analysis followed by an a priori power analysis.
Section 1: Reporting the t-Test Results
Using the supplied data set, conduct an independent samples t-test with extra credit as the grouping variable (no = 1; yes = 2) and Total as the outcome variable.
Paste the output and then report:
The sample size for no (n1) and sample size for yes (n2).
The means for no (M1) and yes (M2) on Total.
The calculated mean difference (M1 – M2).
The standard deviations for no (s1) and yes (s2) on Total.
The Levene test (homogeneity of variance assumption) and interpretation.
t, degrees of freedom, t value, and p value. State whether or not to reject the null hypothesis. Interpret the results.
Calculate Cohen′s d effect size and interpret it. Specifically, if the homogeneity of variance assumption is met, calculate Cohen′s d as described below. Violation of the homogeneity of variance assumption requires calculation of Spooled. Homogeneity assumed:
Cohen′s d = (M1 – M2) ÷ s1 or Cohen′s d = (M1 – M2) ÷ s2.
To be comprehensive, report Cohen′s d based on a calculation with s1 and a calculation with s2. Round the effect size to two decimal places. Interpret Cohen′s d.
Section 2: Post-hoc Power Analysis
Open G*Power. Select the following options:
Test family = t-tests.
Statistical test = Means: Difference between two independent groups (two groups).
Type of power analysis = Post hoc: Compute achieved power.
Tails = Two.
Effect size d = Cohen′s d obtained from Section 1 above (using either s1 or s2).
α err prob = standard alpha level.
Sample size group 1 = n1 from Section 1 above.
Sample size group 2 = n2 from Section 1 above.
Click Calculate.
Provide a screenshot of your G*Power output. Report the observed power of this post-hoc power analysis. Interpret the level of power in terms of rejecting a null hypothesis. Do you have sufficient power to reject a false null hypothesis? Interpret power in terms of committing a Type II error.
Section 3: A Priori Power Analysis
In G*Power, now select:
Type of power analysis = A priori: Compute required sample size.
Input effect size d from Section 1.
Specify α err prob.
Specify Power (1 – β) = .80.
Set the Allocation ratio to 1 (that is, equal sample sizes).
Press Calculate.
Provide a screenshot of your G*Power output. Interpret the meaning of a .80 power value. Specifically, report the estimated n1, n2, and total N to achieve obtain a power of .80. How many total subjects (N) would be needed to obtain a power of .80? Would you have expected a required N of this size? Why or why not?
Next, in G*Power, change the Cohen′s d effect size value obtained in Section 1 and set it to .50 (conventional ″medium″ effect size). Click Calculate. How many total subjects (N) are needed to obtain a power of .80? Compare and contrast these two estimated Ns.
In conclusion, reflect on the importance of conducting an a priori power analysis in psychological research plans.
Additional Requirements
Written communication: Should be free of errors that detract from the overall message.
APA formatting: References and citations are formatted according to current APA style guidelines. Refer to Evidence and APA for more information on how to cite your sources.
Length: 8–10 double-spaced pages, in addition to the title page and references page.

 

Place your order now for a similar assignment and have exceptional work written by our team of experts, At affordable rates

For This or a Similar Paper Click To Order Now

Leave a Comment

Your email address will not be published. Required fields are marked *

Why Choose Us?

Bringing Life to Your Smile
Premium Quality

We have qualified native essay writers from top U.S. universities. Our writers produce high-quality content in all academic subjects.

100% Confidentiality

We ensure to maintain content privacy while helping you in paper writing. You are the copy-write owner of the work. We never reveal your personal information.

Free Proofreading

Our senior team of writers proof-read your document to ensure it has no mistake.

Timely Deliver

We believe in delivering quality work, within your deadline or you should not pay. Our professional writers beat your short deadlines.

100% Confidentiality

We ensure to maintain content privacy while helping you in paper writing. You are the copy-write owner of the work. We never reveal your personal information.

24-7 Support

Our senior team of writers proof-read your document to ensure it has no mistake.

Scroll to Top